Scoring functionality for phrase queries. A document is considered matching if it contains the phrase-query terms at "valid" positions. What "valid positions" are depends on the type of the phrase query: for an exact phrase query terms are required to appear in adjacent locations, while for a sloppy phrase query some distance between the terms is allowed. The abstract method phraseFreq() of extending classes is invoked for each document containing all the phrase query terms, in order to compute the frequency of the phrase query in that document. A non zero frequency means a match. More...

#include <PhraseScorer.h>

Inheritance diagram for Lucene::PhraseScorer:

Public Member Functions
	PhraseScorer (const WeightPtr &weight, Collection< TermPositionsPtr > tps, Collection< int32_t > offsets, const SimilarityPtr &similarity, ByteArray norms)
virtual	~PhraseScorer ()
virtual String	getClassName ()
boost::shared_ptr< PhraseScorer >	shared_from_this ()
virtual int32_t	docID ()
	Returns the following:
virtual int32_t	nextDoc ()
	Advances to the next document in the set and returns the doc it is currently on, or `NO_MORE_DOCS` if there are no more docs in the set.
virtual double	score ()
	Returns the score of the current document matching the query. Initially invalid, until `nextDoc()` or `advance(int32_t)` is called the first time, or when called from within `Collector#collect`.
virtual int32_t	advance (int32_t target)
	Advances to the first beyond the current whose document number is greater than or equal to target. Returns the current document number or `NO_MORE_DOCS` if there are no more docs in the set.
double	currentFreq ()
	Phrase frequency in current doc as computed by phraseFreq().
virtual float	termFreq ()
virtual String	toString ()
	Returns a string representation of the object.
Public Member Functions inherited from Lucene::Scorer
	Scorer (const SimilarityPtr &similarity)
	Constructs a Scorer.
	Scorer (const WeightPtr &weight)
virtual	~Scorer ()
boost::shared_ptr< Scorer >	shared_from_this ()
SimilarityPtr	getSimilarity ()
	Returns the Similarity implementation used by this scorer.
virtual void	score (const CollectorPtr &collector)
	Scores and collects all matching documents.
void	visitSubScorers (QueryPtr parent, BooleanClause::Occur relationship, ScorerVisitor *visitor)
void	visitScorers (ScorerVisitor *visitor)
Public Member Functions inherited from Lucene::DocIdSetIterator
virtual	~DocIdSetIterator ()
boost::shared_ptr< DocIdSetIterator >	shared_from_this ()
Public Member Functions inherited from Lucene::LuceneObject
virtual	~LuceneObject ()
virtual void	initialize ()
	Called directly after instantiation to create objects that depend on this object being fully constructed.
virtual LuceneObjectPtr	clone (const LuceneObjectPtr &other=LuceneObjectPtr())
	Return clone of this object.
virtual int32_t	hashCode ()
	Return hash code for this object.
virtual bool	equals (const LuceneObjectPtr &other)
	Return whether two objects are equal.
virtual int32_t	compareTo (const LuceneObjectPtr &other)
	Compare two objects.
Public Member Functions inherited from Lucene::LuceneSync
virtual	~LuceneSync ()
virtual SynchronizePtr	getSync ()
	Return this object synchronize lock.
virtual LuceneSignalPtr	getSignal ()
	Return this object signal.
virtual void	lock (int32_t timeout=0)
	Lock this object using an optional timeout.
virtual void	unlock ()
	Unlock this object.
virtual bool	holdsLock ()
	Returns true if this object is currently locked by current thread.
virtual void	wait (int32_t timeout=0)
	Wait for signal using an optional timeout.
virtual void	notifyAll ()
	Notify all threads waiting for signal.

Static Public Member Functions
static String	_getClassName ()
Static Public Member Functions inherited from Lucene::Scorer
static String	_getClassName ()
Static Public Member Functions inherited from Lucene::DocIdSetIterator
static String	_getClassName ()

Protected Member Functions
bool	doNext ()
	Next without initial increment.
virtual double	phraseFreq ()=0
	For a document containing all the phrase query terms, compute the frequency of the phrase in that document. A non zero frequency means a match. Note, that containing all phrase terms does not guarantee a match - they have to be found in matching locations.
void	init ()
void	sort ()
void	pqToList ()
void	firstToLast ()
Protected Member Functions inherited from Lucene::Scorer
virtual bool	score (const CollectorPtr &collector, int32_t max, int32_t firstDocID)
	Collects matching documents in a range. Hook for optimization. Note, firstDocID is added to ensure that `nextDoc()` was called before this method.
Protected Member Functions inherited from Lucene::LuceneObject
	LuceneObject ()

Protected Attributes
WeightPtr	weight
Weight *	__weight = nullptr
ByteArray	norms
double	value
bool	firstTime
bool	more
PhraseQueuePtr	pq
std::vector< PhrasePositionsPtr >	_holds
PhrasePositions *	__first = nullptr
PhrasePositions *	__last = nullptr
double	freq
Protected Attributes inherited from Lucene::Scorer
SimilarityPtr	similarity
Protected Attributes inherited from Lucene::LuceneSync
SynchronizePtr	objectLock
LuceneSignalPtr	objectSignal

Additional Inherited Members
Data Fields inherited from Lucene::Scorer
WeightPtr	weight
Static Public Attributes inherited from Lucene::DocIdSetIterator
static const int32_t	NO_MORE_DOCS
	When returned by `nextDoc()`, `advance(int)` and `docID()` it means there are no more docs in the iterator.

Detailed Description

Scoring functionality for phrase queries. A document is considered matching if it contains the phrase-query terms at "valid" positions. What "valid positions" are depends on the type of the phrase query: for an exact phrase query terms are required to appear in adjacent locations, while for a sloppy phrase query some distance between the terms is allowed. The abstract method phraseFreq() of extending classes is invoked for each document containing all the phrase query terms, in order to compute the frequency of the phrase query in that document. A non zero frequency means a match.

Constructor & Destructor Documentation

◆ PhraseScorer()

Lucene::PhraseScorer::PhraseScorer	(	const WeightPtr &	weight,
		Collection< TermPositionsPtr >	tps,
		Collection< int32_t >	offsets,
		const SimilarityPtr &	similarity,
		ByteArray	norms )

References norms, Lucene::Scorer::similarity, and weight.

Referenced by _getClassName().

◆ ~PhraseScorer()

virtual Lucene::PhraseScorer::~PhraseScorer ( )

virtual

Member Function Documentation

◆ _getClassName()

String Lucene::PhraseScorer::_getClassName ( )

inlinestatic

References PhraseScorer().

◆ advance()

virtual int32_t Lucene::PhraseScorer::advance ( int32_t target )

virtual

Advances to the first beyond the current whose document number is greater than or equal to target. Returns the current document number or NO_MORE_DOCS if there are no more docs in the set.

Behaves as if written:

int32_t advance(int32_t target)
{
    int32_t doc;
    while ((doc = nextDoc()) < target)
    { }
    return doc;
}

Some implementations are considerably more efficient than that.

NOTE: certain implementations may return a different value (each time) if called several times in a row with the same target.

NOTE: this method may be called with {@value NO_MORE_DOCS} for efficiency by some Scorers. If your implementation cannot efficiently determine that it should exhaust, it is recommended that you check for that value in each call to this method.

NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behaviour.

Implements Lucene::DocIdSetIterator.

◆ currentFreq()

double Lucene::PhraseScorer::currentFreq ( )

Phrase frequency in current doc as computed by phraseFreq().

Referenced by termFreq().

◆ docID()

virtual int32_t Lucene::PhraseScorer::docID ( )

virtual

Returns the following:

-1 or NO_MORE_DOCS if nextDoc() or advance(int) were not called yet.
NO_MORE_DOCS if the iterator has exhausted.
Otherwise it should return the doc ID it is currently on.

Implements Lucene::DocIdSetIterator.

◆ doNext()

bool Lucene::PhraseScorer::doNext ( )

protected

Next without initial increment.

◆ firstToLast()

void Lucene::PhraseScorer::firstToLast ( )

protected

◆ getClassName()

virtual String Lucene::PhraseScorer::getClassName ( )

inlinevirtual

Reimplemented from Lucene::Scorer.

Reimplemented in Lucene::ExactPhraseScorer, and Lucene::SloppyPhraseScorer.

◆ init()

void Lucene::PhraseScorer::init ( )

protected

◆ nextDoc()

virtual int32_t Lucene::PhraseScorer::nextDoc ( )

virtual

Advances to the next document in the set and returns the doc it is currently on, or NO_MORE_DOCS if there are no more docs in the set.

NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behaviour.

Implements Lucene::DocIdSetIterator.

◆ phraseFreq()

virtual double Lucene::PhraseScorer::phraseFreq ( )

protectedpure virtual

For a document containing all the phrase query terms, compute the frequency of the phrase in that document. A non zero frequency means a match. Note, that containing all phrase terms does not guarantee a match - they have to be found in matching locations.

Returns: frequency of the phrase in current doc, 0 if not found.

Implemented in Lucene::ExactPhraseScorer, and Lucene::SloppyPhraseScorer.

◆ pqToList()

void Lucene::PhraseScorer::pqToList ( )

protected

◆ score()

virtual double Lucene::PhraseScorer::score ( )

virtual

Returns the score of the current document matching the query. Initially invalid, until nextDoc() or advance(int32_t) is called the first time, or when called from within Collector#collect.

Implements Lucene::Scorer.

◆ shared_from_this()

boost::shared_ptr< PhraseScorer > Lucene::PhraseScorer::shared_from_this ( )

inline

◆ sort()

void Lucene::PhraseScorer::sort ( )

protected

◆ termFreq()

virtual float Lucene::PhraseScorer::termFreq ( )

inlinevirtual

Reimplemented from Lucene::Scorer.

References currentFreq().

◆ toString()

virtual String Lucene::PhraseScorer::toString ( )

virtual

Returns a string representation of the object.

Reimplemented from Lucene::LuceneObject.

Field Documentation

◆ __first

PhrasePositions* Lucene::PhraseScorer::__first = nullptr

protected

◆ __last

PhrasePositions* Lucene::PhraseScorer::__last = nullptr

protected

◆ __weight

Weight* Lucene::PhraseScorer::__weight = nullptr

protected

◆ _holds

std::vector<PhrasePositionsPtr> Lucene::PhraseScorer::_holds

protected

◆ firstTime

bool Lucene::PhraseScorer::firstTime

protected

◆ freq

double Lucene::PhraseScorer::freq

protected

◆ more

bool Lucene::PhraseScorer::more

protected

◆ norms

ByteArray Lucene::PhraseScorer::norms

protected

Referenced by Lucene::ExactPhraseScorer::ExactPhraseScorer(), PhraseScorer(), and Lucene::SloppyPhraseScorer::SloppyPhraseScorer().

◆ pq

PhraseQueuePtr Lucene::PhraseScorer::pq

protected

◆ value

double Lucene::PhraseScorer::value

protected

◆ weight

WeightPtr Lucene::PhraseScorer::weight

protected

Referenced by Lucene::ExactPhraseScorer::ExactPhraseScorer(), PhraseScorer(), and Lucene::SloppyPhraseScorer::SloppyPhraseScorer().

The documentation for this class was generated from the following file:

PhraseScorer.h

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ PhraseScorer()

◆ ~PhraseScorer()

Member Function Documentation

◆ _getClassName()

◆ advance()

◆ currentFreq()

◆ docID()

◆ doNext()

◆ firstToLast()

◆ getClassName()

◆ init()

◆ nextDoc()

◆ phraseFreq()

◆ pqToList()

◆ score()

◆ shared_from_this()

◆ sort()

◆ termFreq()

◆ toString()

Field Documentation

◆ __first

◆ __last

◆ __weight

◆ _holds

◆ firstTime

◆ freq

◆ more

◆ norms

◆ pq

◆ value

◆ weight